In tense scenes broadcast on Sunday, viewers saw Mr Bates implicated in the “accident”, after leaving Downton to complete mysterious errands while suspecting Green had attacked his wife.

The death followed the untimely demise of central characters Lady Sybil and Matthew Crawley, played by Jessica Brown Findlay and Dan Stevens respectively, as well as minor characters including aristocrat Lavinia Swire, footman William Mason and a visiting Turkish diplomat.

It was one moment of controversy in the hour and 20 minute-long show, which saw an otherwise gentle end to a tumultuous series.

The next season, now confirmed by ITV, will go on to explore Lady Mary’s relationship with her two would-be suitors, Branson’s flirtation with a village school teacher and Lady Edith’s pregnancy, as well as the fall-out from Lady Rose’s broken engagement.

Viewers will have to wait to learn whether Mr Bates is officially implicated in the death of Green, after Lady Mary appeared to rally to protect him.

Last night, he was seen asking permission to go to York to do “this and that”, before storming up the long drive way of Downton Abbey.

Moments later, viewers learned of the death of Green in London, with his master Lord Gillingham confirming “lots of people” had seen him slip from a crowded pavement into the path of a “bus or lorry”.

Liz Trubridge said the show’s team had been “very conscious” of the effect the deaths of much-loved characters had on viewers, adding: “You don’t want to keep doing that - of course you don’t.”

However, the series finale is unlikely to cause the complaints endured by Downton for its previous dramatic story twists, with more than 400 people already contacting Ofcom over the sexual assault of Anna.

The controversy has helped drive the drama to record results, making it the highest-rated drama broadcast on British television this year with an average 11.8 million viewers.

ITV has now confirmed the show will definitely be returning for a fifth series, following another Christmas special next month.

Gareth Neame, managing director of Carnival Films which makes the show, said: “Audiences have enjoyed their regular Sunday evening visits back to Downton once again this autumn and we are thrilled to produce a new series of the show next year.

“We promise all the usual highs and lows, romance, drama and comedy played out by some of the most iconic characters on television.

“All the actors and makers of the show continue to be humbled by the extraordinary audience response and want to take the show from strength to strength next year”.